I have the same problem,but i don't know the mintmenu quit unexpectedly exactly reason.i try to resolve this problem,so i found when i run python /usr/lib/linuxmint/mintMenu/mintMenu.py manually,it display some message,seems python version problem,so i doubt python version cause the mintmenu quit unexpectedly .

/usr/lib/python2.7/dist-packages/gi/overrides/Gtk.py:48: RuntimeWarning: You have imported the Gtk 2.0 module. Because Gtk 2.0 was not designed for use with introspection some of the interfaces and API will fail. As such this is not supported by the pygobject development team and we encourage you to port your app to Gtk 3 or greater. PyGTK is the recomended python module to use with Gtk 2.0 warnings.warn(warn_msg, RuntimeWarning)

I encountered this error previously when upgrading mate-panel to a version incompatible with the version of mintmenu installed.I resolved the issue by grabbing and installing version 5.4.9 of mintmenu directly from here: http://packages.linuxmint.com/pool/main/m/mintmenu/